Abstract

Background

There is an on-going debate about whether to perform surgery on early stage localised
prostate cancer and risk the common long term side effects such as urinary incontinence
and erectile dysfunction. Alternatively these patients could be closely monitored
and treated only in case of disease progression (active surveillance). The aim of
this paper is to develop a decision-analytic model comparing the cost-utility of active
surveillance (AS) and radical prostatectomy (PE) for a cohort of 65 year old men with
newly diagnosed low risk prostate cancer.

Methods

A Markov model comparing PE and AS over a lifetime horizon was programmed in TreeAge
from a German societal perspective. Comparative disease specific mortality was obtained
from the Scandinavian Prostate Cancer Group trial. Direct costs were identified via
national treatment guidelines and expert interviews covering in-patient, out-patient,
medication, aids and remedies as well as out of pocket payments. Utility values were
used as factor weights for age specific quality of life values of the German population.
Uncertainty was assessed deterministically and probabilistically.

Results

With quality adjustment, AS was the dominant strategy compared with initial treatment.
In the base case, it was associated with an additional 0.04 quality adjusted life
years (7.60 QALYs vs. 7.56 QALYs) and a cost reduction of €6,883 per patient (2011
prices). Considering only life-years gained, PE was more effective with an incremental
cost-effectiveness ratio of €96,420/life year gained. Sensitivity analysis showed
that the probability of developing metastases under AS and utility weights under AS
are a major sources of uncertainty. A Monte Carlo simulation revealed that AS was
more likely to be cost-effective even under very high willingness to pay thresholds.

Conclusion

AS is likely to be a cost-saving treatment strategy for some patients with early stage
localised prostate cancer. However, cost-effectiveness is dependent on patients’ valuation
of health states. Better predictability of tumour progression and modified reimbursement
practice would support widespread use of AS in the context of the German health care
system. More research is necessary in order to reliably quantify the health benefits
compared with initial treatment and account for patient preferences.